1. Field of the Invention
This invention relates in general to the field of automatic screw feeding machines and in particular to the field of fastener driver apparatus and even more in particular to the jaws of the fastener drive apparatus for an automatic screw feeding machine.
2. Description of the Prior Art
Automatic screw feeding machine is the terminology which is commonly applied to a machine which arranges fasteners, such as screws, from a bulk form into an arrangement whereby the fasteners are aligned and then individually delivered to a driver head. The driver head is then utilized to drive a single fastener within a preexisting hole so as to fasten one component to another. The purpose of such machines is, of course, to speed up production by providing rapid fastening of two or more components. Since speed of production is the main objective of such machines, any portion of the machine which tends to jam or malfunction in any manner results in a work stoppage which is contrary to such main objective. Each operation performed upon a fastener which is being utilized within the machine from its bulk supply disposition to its fastened disposition and any point therebetween must necessarily occur in a serial mode whereby one step follows the other. Any one step, therefore, if it is not accomplished properly, will cause a complete shutdown of the machine and production. In today's modern factories, any production shutdown due to a malfunctioning machine must be avoided at all costs.
Screws or other similar fasteners used in industry are mass produced. Mass production generally involves greater tolerances for a given characteristic such as fastener head height, head diameter, or shank diameter, then corresponding individualized custom machining of screws. Automatic screw feeding machines must accommodate such mass-produced fasteners. The greater tolerances of the mass-produced fasteners thereby imposes relatively difficult individualized tasks on automatic screw feeding machines.
One area where an automatic screw feeding machine of the prior art experiences difficulty is in arranging the screws or other fasteners within the jaws of the driver head such that the shank of the screw or fastener is relatively firmly held by the jaws as well as being perpendicular to the jaws. Perpendicularity is important so that an operator may correctly place the screw where it is intended to be placed and the screw is oriented at the correct angle relative to its placement. A misangled or misaligned screw can cause cross threading in a predrilled and tapped hole which, of course, can lead to inadequate fastening of the parts to be joined by the fastener. Accordingly, new, different, and improved apparatus is desired whereby a fastener is relatively firmly held and is properly aligned with regard to the jaws of an automatic driver of an automatic screw feeding machine.
Another area where the prior art automatic screw feeding machines have experienced difficulty is in being able to insert a fastener in a location where there is a relatively small amount of clearance around the head of a fastener. Typically, in the prior art, a type of jaw arrangement known as clam-shell jaws are frequently used. In this type of jaw arrangement, the jaws comprise two movable or rather pivotable members which are arranged such that the front portion in combination provides a cylindrical opening split along the longitudinal sides thereof. The remote end of the jaws are pivotally attached to a housing or other suitable support member whereby the cylindrical portion of the jaws open in a direction away from each other much in the same manner as a clam would open each half of its shell. When the jaws are sufficiently spaced apart from each other, sufficient clearance exists within the cylindrical opening so that the head of the fastener contained therein may pass therethrough upon exiting the jaws of the machine. Clam-shell jaws required a relatively large amount of clearance space around the head of the fastener as installed so as to allow the jaws to open in the manner before mentioned. As can be imagined, there are many applications whereby fasteners are required to be used and a relatively large clearance space around the head of the fasteners is simply not available. In such instances, either the automatic screw feeding machine cannot be used, or the parts to be joined must be redesigned so as to create sufficient clearance. Accordingly, new, different, and improved jaw apparatus is desired whereby a fastener may be inserted in an area where there is relatively little clearance around the head of the fastener.
Still another area in the prior art where improvement may be advantageously utilized is in prevention of marring or scratching of the surface of the product within which the fastener is to be inserted. The prior art movable jaws, such as the previously-described clam-shell type, in many instances, do mar the surface of the product due to the movement of the jaws. Repeated contact of the removable jaws with the product surface can eventually lead to scratching of the jaws which then can further mar the product. Since automatic screw feeding machines are used for mass production, a significant amount of marring can occur before the extraordinary remedy of shutting down production and repairing the offending jaws. Accordingly, jaw apparatus is desired which substantially reduces actual and potential marring of the surface of the product within which a fastener is inserted.
It is to be noted and especially recognized that there are other objects of the present invention which, although not specifically stated but which objects will be obvious to those skilled in the art to which this invention pertains, are intended to be included within the scope of the present invention.